Dream Herb was traditionally used by the Chontal Natives of Oaxaca, Mexico. It would be prepared as a tea and drank while smoking a cigarette made up of the Calea zacatechichi foliage just before going to bed.

Those who partook of the Dream Herb were able to experience lucid dreaming; the ability to control and remember their dreams with less effort. Auditory hallucinations are also fairly common, which prompted the Chontals, believing they were hearing the voice of God, to refer to Calea zacatechici as Leaf of God.

Exactly how Dream Herb (Calea zacatechichi) effects the brain is not well understood. Modern studies have shown an increase in brain activity during sleep and some minor hallucinations of subjects when awake.